关键词: 生态环境需水量, 河流系统, 海滦河流域

Abstract: In the history of water utilization and development, our attention has always been paid on the benefit we could get from rivers while environmental and ecological function of the river system used to be neglected. Thus the activities of water utilization and development were accompanied by more and more serious environmental and ecological problems. In order to reduce the environmental and ecological problems induced by water resources development and utilization, this paper has proposed a concept of environmental and ecological water consumption. In general, we defined that the environmental and ecological water consumption means the minimum water that must be saved in or consumed by the natural water bodies to conserve their environmental and ecological functions. Based on the definition, the methods on calculating the amount of environmental and ecological water consumption are determined. Water consumption can be divided into three parts, i.e. the basic water consumption of rivers, water consumption for transportation of sediments and salts, water consumption for evaporation of the lakes. The methods for calculating the different parts of water consumption were shown in expressions. In a case study on Hai Luanhe Basins, the hydrological records before 1960, which may represent the natural conditions of the river systems, were used for calculating. The results of the calculation have shown that the environmental and ecological water consumption in the Basins is about 124?10 8m³, including 57?10 8m³ for basic consumption, 63?10 8m³ for transportation of sediments and salts and 4?10 8m³ for net evaporation loss of lakes. Thus it was estimated that the total amount of environmental and ecological water consumption accounts 54% of the total amount of runoff (228?10 8m³). However, there are still some aspects of environmental and ecological consumption that are not under our consideration. It should be realized that the required amount of environmental and ecological water consumption must be more than that we have calculated. According to this result, if the rational utilization rate of the runoff in the basins is more than 40%, the problems of eco environment will be serious but the current utilization rate of the Basins is as high as 80%. It is on the urgency to control and adjust water development and utilization to eliminate those problems existed and to avoid the potential ecological or environmental crises that are still not clear.

Key words: environmental and ecological water consumption, river systems, Haihe Luanhe Basins